Watermelon rinds have an amino acid called citrulline.
Citrulline can help get rid of nitrogen in your blood and can also help ease pain if you have sore muscles. In fact, the rind has more citrulline than the juicy flesh. If you’re not keen on eating the rind raw, there are other ways to prepare and eat it. You can pickle it, juice it, or stir fry it like a vegetable.